Astra sprot hatch BTCC - engine options?

#1
Ooops Sport Hatch!!!!

So I went a bit mental and bought this a few months ago. Plan is to use it for trackdays for the next year or 2 then race it in the historic touring car series.

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Swindon have quoted £15k to refresh the original 2.0 NA Sodemo engine – (L850 architecure same as Z22SE) and it needs a refresh every 500 race miles!!!!! So definitely won’t be using this for track days.....

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Q. With a £5k budget what engine would you guys run for track days? I’m not after mega power, the original ‘only’ has 270bhp so similar would be OK. Must be the same bottom end so it mounts to the transmission OK. Cheers
 
#3
a fully 'built' engine strong enough for 400bhp only costs around £4k and that includes a brand new B207 donor engine (y)

But you would need forced induction to get decent power, getting 270bhp out of a NA is damn expensive and why they want £15k
 
#4
Yeah had a mild version of the b207 in mind, just wondered if there are any 2.4 or 2.5 NA options that would get close. Original exhaust and intake could be reused

Correct it has a xtrac 406, will take 300nm so big turbo grunt is a no no
 
#5
my 2.5 vx220 engine has similar power with webcon throttle bodies (271 bhp), so it is possible. But not within your budget.

a standard LE5 2.4 engine would get you nearer the power you seek, up the CR to 11.5:1, fit z22se race cams, +0.5mm valves, supertech double valve springs, balancer delete and a well ported Saab B207 head

Finding a 2.4 is the hardest part, shipping from the states is expensive. But if you could find someone to remove the cylinder head it would be cheaper, the vvt is junk.
 
#9
How much was the 2.5 build?

2.4 Sounds interesting! I can get the le5 bottom end no problem. Whats the expected hp? ...and could I commission you to build it
my 2.5 block cost me £3500 just in parts and that was when the exchange rate was not that bad, I would expect it to be about £4500 now.
That was just for the basic bottom end = block, crank, bearings, pistons and rods :eek:

The 2.4 does not need Darton sleeves, £750 of machine work to fit the Darton sleeves and custom 90mm pistons, so a huge saving if you build a 2.4 LE5 :)
Building an engine is not a problem, I love building them.
 
#15
A few things to consider;

1 - flywheel is probably an eight bolt pattern, z22se + LE5 are both six bolt (new flywheel required)
2 - mapping will be different, trigger wheel should be the same pattern on the 2.0 and 2.4, but not on the z22se (is ECU easily mappable ?)
3 - gear ratios, these may not suit the 7500rpm 2.4 power bands (the extra torque from the 2.4 engine might cover up any ratio issues)

To get 270 out of a 2.0 is no mean feat, I guess it revs it's nuts off :LOL:
 
#16
They were limited to 8.5k rev limit and 40mm single throttle body so 270bhp was amazing.

Crank bolts I'll check when engine out.
Mapping - it has an EFI these are quite common in motorsport apparently if you know of anyone who would be good to sort it nr Bedford?
Gearset I can change I'm getting the box rebuilt
Cheers
 
#19
Such epic cars I'm properly jealous :bored:

I'd just bang a b207 on with a map and save your money.

The 2.4 and 2.5 na engine as good as they are for the power there just not cheap to build as vocky says
 
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#20
Decided to go down the 2.4 na route with b207 head. Better for the box and closer to the original to drive. Should be a straight swap with remap so simple too.
My bro works in the states and is back here frequently so getting the build parts should be ok.
I'm getting a shopping list together,
Q1. How do I get the CR as high as possible? Skim? Custom Pistons? The only forged Pistons I can find are stock CR.
Q2. There are 3 choices of super tech valve springs, what will work best for 8k rpm using the most aggressive race compcams set
 
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